#ifndef COMMON_DATETIMEPARSER_H_
#define COMMON_DATETIMEPARSER_H_

#include <fermat/common/date_time.h>
#include <string>

namespace fermat {

	/*!
	* This class provides a method for parsing dates and times
	* from strings. All parsing methods do their best to
	* parse a meaningful result, even from malformed input
	* strings.
	*
	* The returned DateTime will always contain a time in the same
	* timezone as the time in the string. Call DateTime::makeUTC()
	* with the timeZoneDifferential returned by parse() to convert
	* the DateTime to UTC.
	*
	* Note: When parsing a time in 12-hour (AM/PM) format, the hour
	* (%h) must be parsed before the AM/PM designator (%a, %A),
	* otherwise the AM/PM designator will be ignored.
	*
	* See the DateTimeFormatter class for a list of supported format specifiers.
	* In addition to the format specifiers supported by DateTimeFormatter, an
	* additional specifier is supported: %r will parse a year given by either
	* two or four digits. Years 69-00 are interpreted in the 20th century
	* (1969-2000), years 01-68 in the 21th century (2001-2068).
	*
	* Note that in the current implementation all characters other than format specifiers in 
	* the format string are ignored/not matched against the date/time string. This may
	* lead to non-error results even with nonsense input strings.
	* This may change in a future version to a more strict behavior.
	* If more strict format validation of date/time strings is required, a regular
	* expression could be used for initial validation, before passing the string
	* to DateTimeParser.
	*/
class  DateTimeParser {
public:
	/*!
	* Parses a date and time in the given format from the given string.
	* Throws a SyntaxException if the string cannot be successfully parsed.
	* Please see DateTimeFormatter::format() for a description of the format string.
	* Class DateTimeFormat defines format strings for various standard date/time formats.
	*/
	static bool parse(const std::string& fmt, const std::string& str, DateTime& dateTime, int& timeZoneDifferential);
	
	/*!
	* Parses a date and time in the given format from the given string.
	* Returns true if the string has been successfully parsed, false otherwise.
	* Please see DateTimeFormatter::format() for a description of the format string.
	* Class DateTimeFormat defines format strings for various standard date/time formats.
	*/
	static bool tryParse(const std::string& fmt, const std::string& str, DateTime& dateTime, int& timeZoneDifferential);
	
	/*!
	* Parses a date and time from the given dateTime string. Before parsing, the method
	* examines the dateTime string for a known date/time format.
	* return false if the string cannot be successfully parsed.
	* Please see DateTimeFormatter::format() for a description of the format string.
	* Class DateTimeFormat defines format strings for various standard date/time formats.
	*/
	static bool parse(const std::string& str, DateTime& dateTime, int& timeZoneDifferential);

	/*!
	* Parses a date and time from the given dateTime string. Before parsing, the method
	* examines the dateTime string for a known date/time format.
	* Please see DateTimeFormatter::format() for a description of the format string.
	* Class DateTimeFormat defines format strings for various standard date/time formats.
	* @return false if can not parse successfuly
	*/	
	static bool tryParse(const std::string& str, DateTime& dateTime, int& timeZoneDifferential);

	/*!
	* Tries to interpret the given range as a month name. The range must be at least
	* three characters long. 
	* Returns the month number (1 .. 12) if the month name is valid. Otherwise throws
	* a SyntaxException.
	*/
	static int parseMonth(std::string::const_iterator& it, const std::string::const_iterator& end);

	/*!
	* Tries to interpret the given range as a weekday name. The range must be at least
	* three characters long. 
	* @return the weekday number (0 .. 6, where 0 = Sunday, 1 = Monday, etc.) if the 
	* weekday name is valid. Otherwise throws a SyntaxException.
	*/
	static int parseDayOfWeek(std::string::const_iterator& it, const std::string::const_iterator& end);

		
protected:
	static int parseTZD(std::string::const_iterator& it, const std::string::const_iterator& end);
	static int parseAMPM(std::string::const_iterator& it, const std::string::const_iterator& end, int hour);
};


} 


#endif 